A variety of types of backpacks exist, including those generally known as internal frame or self-contained backpacks, and external frame backpacks. External frame backpacks are particularly well suited for carrying heavy, awkward, or irregular shaped loads. With external backpack systems the load does not necessarily need to be contained to a confined area such as those used in an internal frame or contained backpack. Heavy and bulky loads can be tied down on external frame backpacks conveniently.
One drawback with such external backpacks is that due to the heavy or awkward loads, the user often experiences difficulty in controlling the backpack. A heavy load, especially when carried over long distances or about difficult terrain, tends to cause a backpack to slip or sag upon the user. A common occurrence when the backpack sags upon the user's hips is that extra forces are then needed to be absorbed at the shoulder strap location or at other portions upon the back of the user. Ideally the load is secured primarily at the hip location of the user which allows for proper center of gravity placement, better load bearing strength, and improved control of a loaded backpack.
External frames have been very popular for many years; however, the development of improved internal frame structures has led to a decline in use of external frame systems. Nonetheless, the external frame system has many advantages over internal frames. The external frame allows a more efficient transfer of weight from the back to the shoulders and hips of the user. The frame can be used with a pack to contain standard gear, or may be used with simply the frame to carry odd shapes or very heavy and dense objects such as crates or water cans or even game.
With the more current use of internal frame systems, advanced high tech designs and materials have been utilized. The success of internal frame systems has led designers to create external frame systems that use internal frame technologies. This has led to the current systems being complicated and expensive.
A need exists for a simple, efficient system that is flexible in its use and has components that integrate with other components to form subsystems for backpackers. The external frame is the preferred system because of the inherent load carrying capabilities.
Major drawbacks of current external frame systems involve complicated and expensive structures. A further drawback is that the present external systems do not adequately secure the load and frame of the backpack at the hips of the user. Throughout normal use of walking with a backpack over rugged terrain or even over simple terrain if carrying a heavy load a great distance results in the backpack beginning to sag from the user. The sagging backpack causes discomfort and makes the use of the backpack more and more difficult. Drawbacks of the complex systems include lack of easily replaceable or interchangeable components such as shoulder straps that can be used on either left or right side or hip belt wings that can be used on either side of the frame.
It is thus an object of the present invention to provide alternative external frame backpack that overcomes the drawbacks and limitations of present backpacks and backpack systems.
It is also an object of the present invention to provide an external frame backpack that secures to the hips of the user without undue loosening or sag thereby allowing the user to support the load primarily at the center of gravity.
It is also an object of the present invention to provide an external frame backpack that minimizes weight or stress upon the user's shoulders.
It is also an object of the present invention to provide an external frame backpack that is capable of supporting large load capacities while allowing the user to maintain enhanced control of the backpack.
It is also an object of the present invention to provide an external frame backpack having a rigid hip belt-to-frame attachment that results in an even distribution of weight or forces onto the hips.
It is also an object of the present invention to provide an external frame backpack having a hip pad having minimal load bearing function.
These and other objects of the invention will become apparent in light of the present specification.